2. WHAT IS SCREENING AND WHY DOES
IT NEED TO BE DONE?
Cancer screening aims to detect cancer
before symptoms appear.
This may involve blood tests, urine tests, other
tests, or medical imaging.
The benefits of screening in terms of cancer
prevention, early detection and subsequent
treatment must be weighed against any
harms.
Cancer screening is not indicated unless life
expectancy is greater than five years and the
benefit is uncertain over the age of 70.
3. Screening is not normally useful for rare
cancers.
Countries often focus their screening
recommendations on the major forms of
treatable cancer found in their population.
Screening recommendations depend on the
individual's risk, with high-risk people receiving
earlier and more frequent screening than low-
risk people.
4. ROAD MAP FOR DISCUSSION
I will continue my discussion under the
following headings
A. Breast Cancer Screening
B. Cervical Cancer Screening
C. Colorectal Cancer Screening
D. Genetic Screening
E. Lung Cancer Screening
F. Prostate Cancer Screening
G. Head and Neck Cancer Screening
6. NCCN BREAST SCREENING CONSIDERATIONS
Screening Women at Average Risk
For women between ages 25-40 yrs CBE
recommended every 1 to 3 yrs and breast
awareness encouraged.
For women aged >40 yrs Annual CBE and
screening mammography and breast
awareness is encouraged.
Mammograms can often detect a lesion 2
yrs before the lesion is discovered by CBE.
Yearly screening is thought to be more
beneficial.
7. CONTD..
Screening Women At Increased Risk
Modified Gail Model assesses the risk of
invasive breast cancer as a function of age,
menarche, age at first live birth or nulliparity,
number of first degree relatives with breast
cancer, number of previously benign breast
biopsies, atypical hyperplasia and race.
This model calculates and prints 5-year and
lifetime projected probabilities of developing
invasive breast cancer and identifies increased
risk.
Gail model should not be used for women with
gene mutation, strong family history, prior
thoracic radiation or for those with LCIS.
8. CONTD..
For a woman aged 35 yrs or older with a 5-yr
risk > 1.7% and patients with LCIS, CBE
every 6 to 12 months and annual
mammography along with breast awareness
is encouraged.
For a woman with >20% lifetime risk of
breast cancer (based on family history),
breast awareness and beginning at 30, CBE
every 6 to 12 months and annual
mammography. Annual breast MRI is also
9. CONTD..
For a woman who is a carrier of BRCA 1/2
mutation, CBE every 6-12 mo starting at age
25, breast awareness, annual mammograms
and breast MRI as an adjunct.
10.
11. MAMMOGRAPHIC SCREENING
A screening mammogram typically involves
two x-ray images of each breast, one
craniocaudal and other mediolateral oblique.
Mammography results are mandated to be
reported using BI-RADS developed by the
American College of Radiology.
BI-RADS – Breast Imaging Reporting and
Data System
14. BREAST MRI SCREENING
The sensitivity of breast MRI at detecting breast
cancer is higher than the sensitivity of
mammography, although the specificity of the
former is lower.
NCCN recommends annual MRI as an adjunct
in the following
1. Women with known genetic predisposition for
HBOC starting at age 25.
2. Women with prior thoracic radiation between
ages 10-30 yrs.
3. Women with >20% lifetime risk as described
by ACS guidelines.
16. Women should begin screening at 21yrs of
age, regardless of whether sexual
intercourse has already occurred.
Data indicate that cervical screening should
be avoided in women younger than 21yrs,
because these women are at very low risk of
cervical cancer and because treatment can
lead to complications.
17. CONTD..
After initiation, cervical screening should be
performed every 3 yrs in women 21-29 yrs of
age with cervical cytology alone. However,
women with high risk factors should receive
more frequent screening, usually annually.
Screening for women > 30 yrs include
1. Cervical cytology combined with DNA
testing for high risk HPV types every 5 yrs
(preferred)
2. Cervical cytology alone every 3 yrs.
18.
19. Cervical cytology alone is more effective at
detecting squamous cell carcinoma than
adenocarcinoma. Co-testing is preferred
because HPV DNA testing increases
detection of adenocarcinoma and
adenocarcinoma in situ.
The screening intervals should not be
increased in women 21-65 yrs with negative
tests.
Use of HPV DNA testing alone for screening
is not currently recommended.
20. Cervical cytology screening should be initiated
and should be CONTINUED in women who
have been vaccinated against HPV 16 and 18.
Women previously treated for CIN 2, CIN 3
should CONTINUE to have routine screening for
at least 20 yrs after treatment and after initial
postoperative surveillance, because they remain
at risk for persistent or recurrent disease.
21. Screening can be discontinued after total
hysterectomy for benign disease.
Screening may be discontinued for women
with an intact cervix who are older than 65
yrs with negative previous results and with
no history of abnormal cervical cytology
tests.
Women with co morbid or life threatening
illness may discontinue screening.
23. Screening Modalities that detect Adenomatous
Polyps and Cancer
- Colonoscopy every 10 yrs
- Flexible Sigmoidoscopy every 5 yrs
- CT colonography (CTC) every 5 yrs
Screening modalities that primarily detect
cancer
- Guaiac-based screening
- Immunochemical based testing annually
- Stool DNA test with high sensitivity ( interval
for screening is uncertain)
24. COLONOSCOPY
A 10 yr interval is appropriate for average
risk patients who had an optimal procedure.
Shorter intervals may be indicated based on
the quality and completeness of the
colonoscopy.
Individual risk factors and physician
judgment should be included.
Colonoscopy has limitations and cannot
detect all cancers and polyps.
25.
26. FLEXIBLE SIGMOIDOSCOPY
May be performed alone or in combination
with stool based screening.
Requires no sedation unlike colonoscopy
and less bowel preparation, but is limited to
examination of the lower half of the colon
tract.
Performed using a scope 60cm or longer.
Patients with lesions larger than 1cm should
directly be referred for colonoscopy since
they are almost always adenomatous polyps.
27.
28. COMPUTED TOMOGRAPHIC COLONOGRAPHY
Also known as Virtual colonoscopy or CTC.
Advantage of being noninvasive and not
requiring sedation. However , a positive
finding requires colonoscopy and extra
colonic findings, which are present, pose a
dilemma.
Overall data suggests that CTC may be
useful for the detection of larger polyps
however, it is still an evolving technology.
29. FECAL BASED SCREENING TESTS
Fecal tests are designed to detect signs of CRC
in stool samples, specifically occult blood or
more recently alterations in exfoliated DNA.
They are noninvasive and no bowel clearance is
necessary.
However, they are less likely to detect
adenomatous polyps.
Sensitivity can be limited by inadequate
specimen collection or suboptimal processing.
These tests are recommended annually alone
or in combination with flexible sigmoidoscopy
every 5 years.
30. FECAL OCCULT BLOOD TEST
Two FOBT’s are available – Guaiac based
and Immunochemical.
Guaiac FOBT
- MOA is based on the pseudoperoxidase
activity of heme in blood.
- It is the MC stool test in use for CRC
screening.
- Major disadvantage is that it may miss
tumors that bleed in small amounts,
intermittently or not at all and high false
positive rate
- It should be performed on three successive
31.
32. FECAL OCCULT BLOOD TEST
Fecal Immunochemical Test
- Directly detects human globin within Hb.
- Does not require dietary restrictions and
single sample is sufficient.
- It is more sensitive than guaiac FOBT.
Stool DNA Test
- Emerging screening tool; detects the
presence of known DNA alterations.
- Not yet been approved by FDA and not
considered a first line screening tool.
34. ASCO GENETIC TESTING GUIDELINES 2010
Genetic testing is recommended when there is
1. Personal or family history suggesting genetic
cancer susceptibility.
2. The test can be adequately interpreted.
3. The results will aid in the diagnosis or
influence the medical or surgical
management of the patient or family
members at hereditary risk of cancer.
35. RECOMMENDATIONS FOR HBOC
Considerable initial screening is a reflection
of the early age of onset seen in HBOC.
Women who is a carrier of BRCA 1/2
mutation, training in breast awareness with
regular monthly practice should begin at age
25.
The woman should have annual
mammograms and breast MRI screening
beginning at 25.
Studies show that MRI is more sensitive than
Mammography but the downside is higher
false positive result and higher cost relative
37. GENETICS AND COLORECTAL CANCER
Management of individuals with a family history of
FAP depends on whether the familial mutation is
known or unknown.
Genetic testing of APC and/or MUTYH is important to
differentiate FAP from MAP and colonic polyposis of
unknown etiology.
When a patient with no familial mutation presents
with h/o >10 adenomas, then comprehensive genetic
testing of APC and/or MUTYH is recommended.
MUTYH testing can be performed prior to APC testing
if a recessive pattern is apparent in the pedigree.
Genetic counseling and testing is recommended for
patients with multiple adenomatous polyps.
39. RISK ASSESSMENT
NCCN Screening Panel recommends lung
cancer screening using helical LDCT for
individuals with following high risk factors.
1. 55-74 yrs; 30 or more pack year history and
if former smoker, have quit within 15 yrs.
Annual screening recommended every 2 yrs.
2. >50 yrs; 20 or more pack year history and
additional risk factors.
NCCN Panel does not currently believe that
exposure to second hand smoke is an
independent risk factor because the data is
40. CONTD..
NCCN defines moderate risk individuals as
those aged 50 yrs or older and with a 20 or
more pack-year history but no additional lung
cancer risk factors.
NCCN defines low risk individuals as those
younger than 50 yrs and/or with a smoking
history of fewer than 20 pack-years.
It does not recommend screening for these
individuals.
43. DRE and PSA are the two components used in
Prostate Screening.
TRUS has been associated with a high false
positive rate, making it unsuitable as a
screening tool.
In 2010, ACS recommended that men make an
informed decision about whether to be screened
for prostate cancer.
If screening is done, it should begin at age 50 in
men at average risk who have a life expectancy
of at least 10 yrs.
44.
45. ACS advises that if PSA < 2.5ng/ml, retesting
may need to be done only every 2 yrs.
Men with > 2.5ng/ml should have annual testing.
In May 2013, the American Urological
Association (AUA) released new guidelines
supporting routine use of PSA in healthy men 55
to 69 yrs who are at average risk and are
asymptomatic.
AUA do not recommend testing in men <40 yrs,
40-54 yrs with average risk, >70 yr old males
nor in males with life expectancy less than 10-
46.
47. SUMMARY
Cancer screening is looking for cancer
before a person has any symptoms.
False positive and false negative tests are
possible.
Finding the cancer may not improve the
person’s health or help the person live
longer.
Screening studies are done to see whether
deaths from cancer decrease when people
are screened.
